Conventional equipment for assembling filters, such as furnace filters, require considerable manual labor input to complete the assembly of the filter and surrounding frame. Furnace filter assemblies typically include a square or rectangular chipboard (or heavyweight paper) frame which surrounds and holds in place a filter media pad with or without air flow grid sheets on one or both sides of the filter media pad. Typically, the frame is arranged on a conveyor and workers manually insert the filter media pad (and one or more air flow grid sheets if required) as the filter moves along the conveyor line. Upon insertion of the filter elements into the frame, it is necessary to fold the generally upstanding frame flaps downwardly to a flat position and to hold the flaps in the folded position until the filter travels under stationary "skis" in the apparatus which hold the flaps in the folded position until the frame travels between top and bottom heated plates which reactivate pre-applied glue strips on the chipboard frame.
It is necessary to fold the frame flaps in proper sequence, i.e., the leading and trailing flaps (relative to the direction of movement of the filter assembly on the conveyor) must be folded before the side flaps. Since, however, the flap portions typically do not stand up vertically, it is necessary to open up the side flaps to provide the space necessary to effect folding of the leading and trailing flaps. After the leading and trailing flaps are folded, then the side flaps may be folded and glued to complete the assembly. To the best of applicant's knowledge, manipulation of the side flaps to permit machine folding of the leading and trailing flaps (and then also the side flaps) has always been done manually by workers stationed along the conveyor line.
It is the principal object of this invention to provide a folding apparatus in line with a conveyor, which automatically separates (or opens) the side flaps and then folds the leading and trailing flaps while the filter assembly travels in continuous fashion along the conveyor.
In the exemplary embodiment, conventional filter processing apparatus has been modified to incorporate a pair of rotating augers which are movable between inoperative and operative positions. Once having been moved to the operative position, the augers are then engaged by the typically partially folded side flaps of the filter as the filter proceeds along the conveyor line. The rotating augers open the side flaps and hold them open as the leading flap passes under the conventional stationary skis which fold the leading flap downwardly. At the same time, and while the side flaps are held in the open position by the rotating augers, a retractable ski or kicker is moved downwardly and forwardly (in the direction of movement of the filter) to fold the trailing filter flap. This retractable ski is positioned, and its movement timed, such that it will fold the trailing flap and hold same in the folded position until same moves under the stationary skis while the augers continue to hold the side flaps in the open position. With the leading and trailing flaps thus held in a folded position by the stationary skis, the filter continues to travel past the rotating augers and, almost immediately, conventional side edge guides downstream of the augers are utilized to fold the side flaps downwardly in overlapping relationship with the already folded leading and trailing flaps. Depending on the length and speed of the conveyor, i.e., closeness of the filters, it may be desirable to retract the augers to an inoperative position at the exit of each filter--retraction of the augers is an optional operation. Thereafter, the filter assembly is immediately passed between top and bottom heating plates which hold all of the flaps in the folded position while pre-applied glue strips (along the frame edges) are heat activated to complete the assembly process.
In its broader aspects therefore, the present invention relates to an apparatus for assembling a filter media pad in a filter frame wherein the filter frame includes upstanding forward, rearward and side flaps, the improvement comprising a pair of rotatable augers arranged to engage the side flaps of the filter and to move the side flaps outwardly to permit folding of the forward and rearward flaps.
In another aspect, the invention provides an apparatus for use in a filter assembly operation wherein filter components are seated within a filter frame such that the frame has a generally upstanding leading flap, side flaps and a trailing flap, the apparatus comprising side flap engaging members adapted to push the pair of side flaps outwardly to provide clearance necessary to close the leading and trailing flaps; a stationary ski member located downstream of the side flap engaging members and adapted to close the leading flap; and a retractable ski member located at least partially upstream of the retractable side flap engaging members and adapted to close the trailing flap, thereby permitting the side flaps to be subsequently closed in an overlapping relationship with the leading and trailing flaps.
In still another aspect, the present invention relates to apparatus for assembling a filter including a frame surrounding and supporting a filter media pad, the frame having forward, side and trailing flaps adapted for folding downwardly into engagement with the filter media pad, the apparatus comprising a conveyor for feeding a plurality of filters in a first direction; first means for opening the side flaps on the conveyor; second means for closing the forward flap; third means for folding the rear flap; fourth means for folding the side flaps; and fifth means for holding the front, rear and side flaps in a folded condition.
In still another aspect, the invention relates to a process for closing open forward, trailing and side flaps of a frame about an insert seated within the frame, and wherein the frame includes at least partially open forward, trailing and side flaps, the method comprising the steps of:
a) feeding the frame and insert continuously in a first linear direction;
b) engaging the side flaps of the frame by a pair of rotating members to move the side flaps outwardly to a fully open position during continuous linear movement of the frame and insert;
c) folding the forward and trailing flaps to a closed position while the side flaps are engaged by the pair of rotating members; and
d) folding the side flaps downwardly to a closed position, overlapping the forward and rearward flaps.
By modifying the conventional filter processing apparatus as described above, considerable manpower is saved in the filter assembly process. Other objects and advantages of the invention will become apparent from the detailed description which follows.